With the unceasing development of computer, communication and customer electronic (3C) industry, the display device in the 3C industry becomes more important. The display device in a 3C product usually uses a backlight module or a front light module. The backlight module or the front light module can guide the light emitted by an external light source of the display device, toward a display panel in the display device for image display. For a non-self emissive display device such as a liquid crystal display (LCD) device, it performs the image display by controlling the optical path of light emitted by the external light source, and therefore requires a corresponding backlight module or a corresponding front light module to guide the light toward the display panel. Recently, with the enhancement of the demand of backlight module or front light module in the large-size LCD device, the backlight module or the front light module requires the uniform emitted light more seriously.
The front backlight module generally utilizes a specific light guiding plate which allows ambient light to pass through and then travel to the LCD panel, or guides the light emitted by a side light source at the side of the light guiding plate, to the LCD panel. However, such a light guiding plate has a low efficiency, leading in the large consumption of light energy. Also, after the light is reflected and refracted in the light guiding plate, the light difficultly arrives where is far from the light source in the light guiding plate, so that the display device easily has a dark area that the place where the light does not arrive, has a low brightness. Therefore, the display device will have an uneven light distribution. In order to maintain the desired brightness of light emitted by the light guiding plate, the power of battery supporting the brightness maintaining is required much more, so that the battery for the power needs to be charged very often. Moreover, the guiding structures of most light guiding plates also cause unclear image problems such as the image distortion or the image blurring.